Re: [CAD_CAM_EDM_DRO] Help: PCB Trace Milling Software

Dennis,

Sounds interesting. Getting the traces into .DXF is still a problem. I
was planning to use ViewCompanion, but .DXF output won't be in until
2.0. And that also depends on what they do with the HPGL files. If
they realize that four or five pen lines side by side are a "trace" and
generate a .DXF line with width, we may have it. Eagle (PCB layout) and
ViewCompanion can also generate Gerber files, which might be easier to
convert into "objects" that a CAD/CAM program can generate tool paths
for.

Well, at least that's my observations for now. I would think there
would be a market for low cost CAD/CAM software that can create
"objects" from either Gerber or HPGL plots of small boards. Ztrace
looks like it might do it, I'm checking it now (well, it didn't like
THAT file), and Deskam2000 is a definate possibility! And yes, I'd like
to checkout SuperCam!

Alan



Dennis Bohlke wrote:

>
> If you can create a DXF file with polylines that have width. SuperCam can
> read them an then the OFFSET command can be used to create the tool offsets.
>
> The Demo version will G-code files.
> http://www.super-tech.com/root/scdemo.htm
>
> I just got this part working.
>
> Dennis Bohlke
>
> ----- Original Message -----
> From: Jon Elson <jmelson@...>
> To: <CAD_CAM_EDM_DRO@egroups.com>
> Sent: Monday, October 16, 2000 9:22 AM
> Subject: Re: [CAD_CAM_EDM_DRO] Help: PCB Trace Milling Software
>
> >
> >
> > Alan Marconett KM6VV wrote:
> >
> > > So how do we get from Gerber files to CNC files? As you observe, the
> > > Gerber "plots" each trace, what we want is contours AROUND the traces!
> > >
> > > I examined an HPGL PCB plot file (see View Companion), and studied how
> > >
> > > multiple pen lines were combined to draw a trace.
> >
> > I figured out a VERY crude algorithm to do this, if anyone wants to try
> > it.
> > First, you map the extent of the drawing onto a bitmap. You then draw
> > in the
> > traces and pads, with the actual width or dimensions of the object. For
> > instance,
> > if the grid is 1 mil, then a 50 mil trace would be drawn by filling in a
> > 50 bits wide
> > track from start to finish.
> >
> > After this is all done, both traces and pads, you could raster through
> > the thing,
> > identifying all points where you cross from one 'color' to another. You
> > have to do
> > this in both axes to make sure you completely surround the traces and
> > pads.
> > This should define a 'border' as a closed pattern of border bits.
> >
> > A second pass could define all separated borders by starting randomly at
> > the
> > first border seen and following all the way around its edge until you
> > get back to
> > the starting point, and numbering all these bits as part of border # 1.
> > You then scan for the next unmarked border, and follow it, marking it
> > #2.
> > You repeat this until there are no unmarked border bits left in the map.
> >
> > You can now check each border to see which side it encloses from some
> > starting
> > point, and create offset tool paths to cut them out.
> >
> > This actually doesn't sound so difficult, now that I have kind of
> > figured
> > out how it can be done. It could be a memory hog for large boards,
> > however.
> >
> > Jon